Nationally-recognised studies and our contacts with a diverse group of industry representatives, non-governmental organisations, and academic researchers show that key barriers to CCS deployment include (1) underdeveloped and costly CO2 capture technology and (2) regulatory and legal uncertainties over CO2 capture, injection, and storage. Among the key technological barriers are a lack of experience in capturing significant amounts of CO2 from power plants and the significant cost of capturing CO2, particularly from existing coal-fired power plants, which are the single largest source of CO2 emissions in the United States. Compounding these technological issues are regulatory and legal uncertainties, including uncertainty regarding liability for CO2 leakage and ownership of CO2 once injected. According to the IPCC, the National Academy of Sciences, and other knowledgeable authorities, another barrier is the absence of a national strategy to control CO2 emissions (emissions trading plan, CO2 emissions tax, or other mandatory control of CO2 emissions), without which the electric utility industry has little incentive to capture and store its CO2 emissions. Moreover, according to key agency officials, the absence of a national strategy has also deterred their agencies from addressing other important practical issues, such as resolving how stored CO2 would be treated in a future CO2 emissions trading plan.